/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.rest.handler.job;

import org.apache.flink.api.common.JobID;
import org.apache.flink.api.common.time.Time;
import org.apache.flink.runtime.executiongraph.AccessExecution;
import org.apache.flink.runtime.executiongraph.AccessExecutionGraph;
import org.apache.flink.runtime.executiongraph.AccessExecutionJobVertex;
import org.apache.flink.runtime.executiongraph.AccessExecutionVertex;
import org.apache.flink.runtime.jobgraph.JobVertexID;
import org.apache.flink.runtime.rest.NotFoundException;
import org.apache.flink.runtime.rest.handler.HandlerRequest;
import org.apache.flink.runtime.rest.handler.legacy.ExecutionGraphCache;
import org.apache.flink.runtime.rest.handler.legacy.metrics.MetricFetcher;
import org.apache.flink.runtime.rest.messages.EmptyRequestBody;
import org.apache.flink.runtime.rest.messages.JobIDPathParameter;
import org.apache.flink.runtime.rest.messages.JobVertexDetailsInfo;
import org.apache.flink.runtime.rest.messages.JobVertexIdPathParameter;
import org.apache.flink.runtime.rest.messages.JobVertexMessageParameters;
import org.apache.flink.runtime.rest.messages.MessageHeaders;
import org.apache.flink.runtime.rest.messages.ResponseBody;
import org.apache.flink.runtime.rest.messages.job.SubtaskExecutionAttemptDetailsInfo;
import org.apache.flink.runtime.webmonitor.RestfulGateway;
import org.apache.flink.runtime.webmonitor.history.ArchivedJson;
import org.apache.flink.runtime.webmonitor.history.JsonArchivist;
import org.apache.flink.runtime.webmonitor.retriever.GatewayRetriever;

import javax.annotation.Nullable;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Executor;

/**
 * Request handler for the job vertex details.
 */
public class JobVertexDetailsHandler extends AbstractExecutionGraphHandler<JobVertexDetailsInfo, JobVertexMessageParameters> implements JsonArchivist {
	private final MetricFetcher metricFetcher;

	public JobVertexDetailsHandler(
			GatewayRetriever<? extends RestfulGateway> leaderRetriever,
			Time timeout,
			Map<String, String> responseHeaders,
			MessageHeaders<EmptyRequestBody, JobVertexDetailsInfo, JobVertexMessageParameters> messageHeaders,
			ExecutionGraphCache executionGraphCache,
			Executor executor,
			MetricFetcher metricFetcher) {
		super(
			leaderRetriever,
			timeout,
			responseHeaders,
			messageHeaders,
			executionGraphCache,
			executor);
		this.metricFetcher = metricFetcher;
	}

	@Override
	protected JobVertexDetailsInfo handleRequest(
			HandlerRequest<EmptyRequestBody, JobVertexMessageParameters> request,
			AccessExecutionGraph executionGraph) throws NotFoundException {
		JobID jobID = request.getPathParameter(JobIDPathParameter.class);
		JobVertexID jobVertexID = request.getPathParameter(JobVertexIdPathParameter.class);
		AccessExecutionJobVertex jobVertex = executionGraph.getJobVertex(jobVertexID);

		if (jobVertex == null) {
			throw new NotFoundException(String.format("JobVertex %s not found", jobVertexID));
		}

		return createJobVertexDetailsInfo(jobVertex, jobID, metricFetcher);
	}

	@Override
	public Collection<ArchivedJson> archiveJsonWithPath(AccessExecutionGraph graph) throws IOException {
		Collection<? extends AccessExecutionJobVertex> vertices = graph.getAllVertices().values();
		List<ArchivedJson> archive = new ArrayList<>(vertices.size());
		for (AccessExecutionJobVertex task : vertices) {
			ResponseBody json = createJobVertexDetailsInfo(task, graph.getJobID(), null);
			String path = getMessageHeaders().getTargetRestEndpointURL()
				.replace(':' + JobIDPathParameter.KEY, graph.getJobID().toString())
				.replace(':' + JobVertexIdPathParameter.KEY, task.getJobVertexId().toString());
			archive.add(new ArchivedJson(path, json));
		}
		return archive;
	}

	private static JobVertexDetailsInfo createJobVertexDetailsInfo(AccessExecutionJobVertex jobVertex, JobID jobID, @Nullable MetricFetcher metricFetcher) {
		List<SubtaskExecutionAttemptDetailsInfo> subtasks = new ArrayList<>();
		final long now = System.currentTimeMillis();
		for (AccessExecutionVertex vertex : jobVertex.getTaskVertices()) {
			final AccessExecution execution = vertex.getCurrentExecutionAttempt();
			final JobVertexID jobVertexID = jobVertex.getJobVertexId();
			subtasks.add(SubtaskExecutionAttemptDetailsInfo.create(execution, metricFetcher, jobID, jobVertexID));
		}

		return new JobVertexDetailsInfo(
			jobVertex.getJobVertexId(),
			jobVertex.getName(),
			jobVertex.getParallelism(),
			now,
			subtasks);
	}
}
